Topic 10: Chemistry of the environment Flashcards
(32 cards)
What colour change occurs when water is added to anhydrous cobalt(II) chloride?
It turns from blue to pink.
What colour change occurs when water is added to anhydrous copper(II) sulfate?
It turns from white to blue.
What are the melting and boiling points of pure water?
Melting point is 0°C, boiling point is 100°C.
Why is distilled water used in chemistry experiments instead of tap water?
Because it contains fewer chemical impurities.
What is sedimentation in water treatment?
A process where small particles clump together and settle out.
How are solids removed from water during filtration?
Water passes through sand and gravel to remove larger insoluble particles.
Why is carbon added to water during treatment?
To remove taste and odour.
What is the role of chlorination in water treatment?
Chlorine is added to kill harmful microbes.
What is the approximate composition of clean, dry air?
78% nitrogen, 21% oxygen, 1% other gases (noble gases and carbon dioxide).
What is the source of carbon dioxide in the air?
Complete combustion of carbon-containing fuels.
What is the source of carbon monoxide and particulates?
Incomplete combustion of carbon-containing fuels.
Where does methane come from?
Decomposition of vegetation and animal digestion gases.
How are oxides of nitrogen produced?
From car engines at high temperatures.
What causes sulfur dioxide pollution?
Burning fossil fuels containing sulfur compounds.
What is the effect of carbon dioxide on the environment?
Causes global warming and climate change.
Why is carbon monoxide dangerous?
It’s a toxic gas that blocks oxygen transport in blood.
What is the effect of particulates?
Causes respiratory problems and cancer.
What is the effect of methane on the environment?
Contributes to global warming and climate change.
What are the effects of oxides of nitrogen?
Causes acid rain and respiratory problems.
What is the environmental effect of sulfur dioxide?
Causes acid rain.
How can we reduce climate change?
Plant trees, reduce livestock farming, use less fossil fuel, use renewable energy.
How can we reduce acid rain?
Use low-sulfur fuels, flue gas desulfurisation, and catalytic converters.
How do greenhouse gases cause global warming?
They absorb and re-emit infrared radiation, trapping heat in the Earth’s atmosphere
What do catalytic converters contain?
Transition metals like platinum and rhodium.
